// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/template_util.h"

#include <string>

#include "testing/gtest/include/gtest/gtest.h"

namespace base {
namespace {

    enum SimpleEnum { SIMPLE_ENUM };
    enum EnumWithExplicitType : uint64_t { ENUM_WITH_EXPLICIT_TYPE };
    enum class ScopedEnum { SCOPED_ENUM };
    enum class ScopedEnumWithOperator { SCOPED_ENUM_WITH_OPERATOR };
    std::ostream& operator<<(std::ostream& os, ScopedEnumWithOperator v)
    {
        return os;
    }
    struct SimpleStruct {
    };
    struct StructWithOperator {
    };
    std::ostream& operator<<(std::ostream& os, const StructWithOperator& v)
    {
        return os;
    }

    // is_non_const_reference<Type>
    static_assert(!is_non_const_reference<int>::value, "IsNonConstReference");
    static_assert(!is_non_const_reference<const int&>::value,
        "IsNonConstReference");
    static_assert(is_non_const_reference<int&>::value, "IsNonConstReference");

    class AssignParent {
    };
    class AssignChild : AssignParent {
    };

    // is_assignable<Type1, Type2>
    static_assert(!is_assignable<int, int>::value, "IsAssignable"); // 1 = 1;
    static_assert(!is_assignable<int, double>::value, "IsAssignable");
    static_assert(is_assignable<int&, int>::value, "IsAssignable");
    static_assert(is_assignable<int&, double>::value, "IsAssignable");
    static_assert(is_assignable<int&, int&>::value, "IsAssignable");
    static_assert(is_assignable<int&, int const&>::value, "IsAssignable");
    static_assert(!is_assignable<int const&, int>::value, "IsAssignable");
    static_assert(!is_assignable<AssignParent&, AssignChild>::value,
        "IsAssignable");
    static_assert(!is_assignable<AssignChild&, AssignParent>::value,
        "IsAssignable");

    struct AssignCopy {
    };
    struct AssignNoCopy {
        AssignNoCopy& operator=(AssignNoCopy&&) { return *this; }
        AssignNoCopy& operator=(const AssignNoCopy&) = delete;
    };
    struct AssignNoMove {
        AssignNoMove& operator=(AssignNoMove&&) = delete;
        AssignNoMove& operator=(const AssignNoMove&) = delete;
    };

    static_assert(is_copy_assignable<AssignCopy>::value, "IsCopyAssignable");
    static_assert(!is_copy_assignable<AssignNoCopy>::value, "IsCopyAssignable");

    static_assert(is_move_assignable<AssignCopy>::value, "IsMoveAssignable");
    static_assert(is_move_assignable<AssignNoCopy>::value, "IsMoveAssignable");
    static_assert(!is_move_assignable<AssignNoMove>::value, "IsMoveAssignable");

    // A few standard types that definitely support printing.
    static_assert(internal::SupportsOstreamOperator<int>::value,
        "ints should be printable");
    static_assert(internal::SupportsOstreamOperator<const char*>::value,
        "C strings should be printable");
    static_assert(internal::SupportsOstreamOperator<std::string>::value,
        "std::string should be printable");

    // Various kinds of enums operator<< support.
    static_assert(internal::SupportsOstreamOperator<SimpleEnum>::value,
        "simple enum should be printable by value");
    static_assert(internal::SupportsOstreamOperator<const SimpleEnum&>::value,
        "simple enum should be printable by const ref");
    static_assert(internal::SupportsOstreamOperator<EnumWithExplicitType>::value,
        "enum with explicit type should be printable by value");
    static_assert(
        internal::SupportsOstreamOperator<const EnumWithExplicitType&>::value,
        "enum with explicit type should be printable by const ref");
    static_assert(!internal::SupportsOstreamOperator<ScopedEnum>::value,
        "scoped enum should not be printable by value");
    static_assert(!internal::SupportsOstreamOperator<const ScopedEnum&>::value,
        "simple enum should not be printable by const ref");
    static_assert(internal::SupportsOstreamOperator<ScopedEnumWithOperator>::value,
        "scoped enum with operator<< should be printable by value");
    static_assert(
        internal::SupportsOstreamOperator<const ScopedEnumWithOperator&>::value,
        "scoped enum with operator<< should be printable by const ref");

    // operator<< support on structs.
    static_assert(!internal::SupportsOstreamOperator<SimpleStruct>::value,
        "simple struct should not be printable by value");
    static_assert(!internal::SupportsOstreamOperator<const SimpleStruct&>::value,
        "simple struct should not be printable by const ref");
    static_assert(internal::SupportsOstreamOperator<StructWithOperator>::value,
        "struct with operator<< should be printable by value");
    static_assert(
        internal::SupportsOstreamOperator<const StructWithOperator&>::value,
        "struct with operator<< should be printable by const ref");

    // underlying type of enums
    static_assert(std::is_integral<underlying_type<SimpleEnum>::type>::value,
        "simple enum must have some integral type");
    static_assert(
        std::is_same<underlying_type<EnumWithExplicitType>::type, uint64_t>::value,
        "explicit type must be detected");
    static_assert(std::is_same<underlying_type<ScopedEnum>::type, int>::value,
        "scoped enum defaults to int");

    struct TriviallyDestructible {
        int field;
    };

    class NonTriviallyDestructible {
        ~NonTriviallyDestructible() { }
    };

    static_assert(is_trivially_destructible<int>::value, "IsTriviallyDestructible");
    static_assert(is_trivially_destructible<TriviallyDestructible>::value,
        "IsTriviallyDestructible");
    static_assert(!is_trivially_destructible<NonTriviallyDestructible>::value,
        "IsTriviallyDestructible");

} // namespace
} // namespace base
